iMXQpro V1 and V2 owners may have seen an entry in the Settings area related to the power key/button.
The following menu is shown if you click the Settings icon (normally one or two cogs) on your homescreen.
Scroll down a line and almost to the end on the right, where you will see a “Power key definition” entry, please click it.
Now select the Shutdown option
The next time you turn your device off, you should see this menu, select Power off
You should now find you can turn your iMXQpro V1 or V2 back on again using the remote control, without any problems.